Interpretive Summary: Leishmania species, Trypanosoma cruzi, and Toxoplasma gondii are single-celled parasite of all warm-blooded hosts. Tissue phases of these parasites are difficult to identify in histological sections. In the present paper, scientists at the Beltsville Agricultural Research Center and from an University in North Carolina report prevalence of these parasites in dogs from Sri Lanka and India. The results will be of interest to biologists, parasitologists, and veterinarians.

Technical Abstract:
The global distribution of leishmaniasis is rapidly expanding into new geographic regions. Dogs are the primary reservoir hosts for human visceral leishmaniasis (VL) caused by infection with Leishmania infantum. Natural infections with other Leishmania species can occur in dogs, but their role as reservoir hosts for other species of Leishmania is uncertain. The Asian countries of India, Nepal, and Bangladesh are among the five countries worldwide with the majority of all human cases of VL. In the present study, serum from 49 dogs from India and 114 dogs from Sri Lanka were examined for antibodies to visceralizing Leishmania parasites. Sera were tested by the canine immunochromatographic strip assays based on recombinant K39 antigen. Antibodies to Leishmania were not detected in any of the dogs tested from India. Anti-Leishmania antibodies were detectable in 1 of 114 dogs from Sri Lanka. The lack of antibodies to Leishmania verifies that dogs are not important reservoir hosts for human VL in India, but serological evidence suggests that leishmaniasis may be an emerging zoonosis in Sri Lanka.